Traditional measures of periodontal disease activity (erythema, bleeding on probing, suppuration and pocket depth), while reflecting some degree of pathology in the tissues, are not reflective of disease activity as defined by loss of periodontal attachment or loss of alveolar bone. Consequently, specific and sensitive measures of periodontal disease activity are required. While considerable effort has been devoted to defining the chemistry of gingival crevicular fluid (GCF), to date GCF analysis has not aided the clinician in managing the periodontal patient. A careful review of this literature, however, indicates that problems exist in regard to the methodology of previous studies. Work in our laboratory has suggested a technique for GCF chemistry that involves sampling of individual crevicular sites for 30 seconds using precut filter paper strips. The volume of fluid is quantitated using a calibrated GCF meter, and then the material on the strip is eluted into 300-400 Mul of diluent. Aliquots of the diluent are then used to evaluate multiple constituents in the sample. The advantages of this technique are: 1. The sample of GCF represents the fluid present in the crevice. Collecting a standardized 1, 2 or 5 Mul from any one site causes contamination of GCF with serum from disrupted capillary beds. 2. The volumetric requirements of the analytical assays are met, and 3. Multiple components in the GCF can be analyzed from the same sample. Our studies with this system suggests that GCF can be a sensitive measure of pathology in the periodontium. This proposal intends to utilize a GCF chemical profile to evaluate periodontal disease activity (loss of periodontal attachment, occurrence of a periodontal abscess or loss of osseous support upon radiographic evaluation). Specifically, this project will analyze GCF samples from the individual crevicular sites for the: 1. Activity of the enzymes beta-glucuronidase, arylsulfatase, collagenase (active and total) and prolidase using spectrophotometric techniques, and 2. Use immunodiffusion techniques to analyze for the antiproteases alpha-1-antitrypsin and alpha-2-macroglobulin, and the systemic marker of inflammation C-reactive protein. By evaluating factors intimately involved in the inflammatory reaction, and the breakdown of nonmineralized and mineralized connective tissue, this research project will determine if changes in the pattern of the GCF profile precede, coincide with or follow the onset of periodontal disease activity in man.